Study On Ceramic Coating Resisting Wear, Corrosion And Oxidation At High Temperature

In this paper, the ceramic coating was studied to be prepared on stainless steel base. The purpose of this study is to improve the properties of stainless steel to resist wear, corrosion and oxidation in high temperature.First, we prepared ceramic coating used at relatively high temperature. The effect of Al/P of bond and aggregate size on the coating wear-resistance property was described. It was found that the coating with excellent properties was prepared. This coating could bear over 8 times thermal lash of cold and heating circulation between 20℃and 450℃. And the coating can be used in condition of 500℃.Second, we prepared ceramic coating used at higher temperature. The method of firing coating at high temperature was used. The properties of coating to resist wear, corrosion and oxidation were tested. And the adhesion between the coating and the steel base was studied. The result showed that the coating had a series of good properties.The addition of sodium carboxymethyl cellulose can obtain ideal stability and dispersion for coating serosity. The stability and dispersion of serosity was improved because of static place obstruct domino offect. The study showed that stability and dispersion was the best by adding 0.15% sodium carboxymethyl cellulose at PH=7-8. The abrasive resistance was improved as the super fine powder was added. And the abrasive resistance was improved when ZrSiO4 was added 15%. The property to resist oxidation was tested by the method of weight increasing because of oxidation. The oxidizing speed of sample of stainless steel without coating was always high. And the oxidizing speed of the sample with coating was lower. As the time was going the weight increased. But the oxidizing speed of sample with coating was always lower than that of the sample without coating. There was a transition layer between the coating and base through SEM photograph of coating interface. The study showed that the thermal shock resistance is improved by pre-oxidizing steel base. The fastness associative oxide with pore was formed when we oxidized the steel base with H2SO4 (98%). The forming of transition layer strengthened adhesion between the coating and the base. The property of thermal shock resistance is the best through pre-oxidizing the base. And we tested the adhesion between the base and coating by turning coating. It was found that the turned face was smooth, and the adhesion of coating was fastness.At last, we prepared functionally graded coating by means of vacuum burning way. The experiment showed that the thermal shock resistance of functionally graded coating is better than one layer coating.